One of the arguments offered by those in support of homosexuality is that it is an orientation and that people are born with and it is the same as being born with a given hair colour. The implication is that since they are said to be born gay, then it is normal and morally acceptable. But there are two problems with this theory.
If genetics determine sexual orientation, then it should be manifested when studying twins who share the exact same genetic information. However, that is not the case. Therefore, homosexuality is a learned behaviour and should be called a preference, not an orientation.
The problem with using genetics as an excuse to justify behaviour is that whatever tendency we might be born with must be considered normal. This includes lying, pedophilia, etc. But, such a logical inference will not be acceptable to the pro-homosexual community because selective statistics and discriminatory reasoning are offered to justify their behaviour.